It is known to prepare flexible explosive compositions of high power by mixing a high explosive, such as RDX, and a high viscosity nitrocellulose containing a nonenergetic organic plasticizer, e.g. tributyl acetylcitrate, alone or in mixture with an energetic plasticizer of the organic polyol nitrate ester type, e.g. trimethylolethane trinitrate (TMETN) (U.S. Pat. Nos. 3,317,361, 3,354,010 and 3,400,025). It is also known to prepare flexible explosive compositions from a high explosive such as RDX and a high viscosity nitrocellulose by employing TMETN in the absence of a non-energetic plasticizer, as disclosed in my copending U.S. application Ser. No. 454,900, filed Mar. 26, 1974, and now U.S. Pat. No. 3,943,017. Such compositions represent valuable improvements in the art, but they are still deficient in one or more significant properties, notably explosive power, flexibility at low temperatures, e.g. -40.degree. F., ease of manufacture, etc.